(1) Field of the Invention
This invention relates to a gas purification system comprising: a first treatment apparatus adapted to purify an untreated feed gas into a primary treated gas by introducing the untreated gas through a feed conduit for herein causing same to contact with an alkaline absorbent liquid so that soluble ingredients in the untreated gas, particularly HCN gas, H.sub.2 S gas and NH.sub.3 gas, are absorbed in the absorbent liquid; an absorbent-liquid-resuscitation apparatus adapted to refresh the used absorbent liquid fed from the said first treatment apparatus as bottom effluent thereof containing the soluble gases, by bubblingly introducing herein a resuscitation gas, containing O.sub.2 gas, while purging out waste or effluent gas herefrom, and to feed back the thusly refreshed absorbent liquid into the first treatment apparatus; and a second treatment apparatus adapted to further purify the said primary treated gas into a secondary treated gas by introducing the primary treated gas fed from the said first treatment apparatus as top effluent thereof, through a feed conduit for herein strippingly capturing any possible remnant NH.sub.3 gas still present therein.
(2) Description of the Prior Art
The system as mentioned hereinabove is supposed to deal with the untreated feed gas such for instance as the fuel gas obtained by coal carbonization, as contains therein toxic ingredients such as HCN gas, H.sub.2 S gas and NH.sub.3 gas, which will thus cause public nuisance when emitted into the atmospheric air and/or aqueous system; namely to purify such feed gas, or more specifically to remove the toxic ingredients from same to ultimately result in a harmless gas as will incur no public nuisance any more; and the conventional system of such type is visualized by a flow diagram as shown in FIG. 4, but there still remains much to be improved in such conventional system. Thus, the system, having been in the construction adopting separate individual nozzles (20a), (20b)--respectively for the bottom effluent of the absorbent liquid from the first treatment apparatus (5), containing the soluble gases, and for air, as used here as the resuscitation gas--for feeding them to absorbent liquid accommodated within the absorbent-liquid-resuscitation apparatus (9), has resulted in rather poor gas/liquid contact efficiency in the resuscitation apparatus (9), requiring therefore big amount of the air in order to resuscitate the absorbent liquid sufficiently enough, consequently incurring uprise in both the installation cost and the operation cost for such air supply, followed by another inconvenience of accordingly increasing the waste effluent gas from the resuscitation apparatus (9), and yet further making it necessary to properly treat such waste effluent gas with an additional separate apparatus (21)--other than the second treatment apparatus (12) for stripping the primary treated gas, from the first treatment apparatus (5), of NH.sub.3 --in view that such waste effluent gas contains therein, as remnant ingredients, NH.sub.3 gas and slight amount of H.sub.2 S gas, as well as substantial amount of O.sub.2 gas, and such system has therefore been disadvantageous in the viewpoint of its initial installation and its running administration, as well.